Mobile robots are becoming increasingly commonplace and are used in such diverse fields as space exploration, lawn mowing and floor cleaning. Recently there has been a rapid advancement in the field of robotic cleaning devices, especially robot vacuum cleaners and floor mopping robots, the primary objective of which is to navigate a user's home autonomously and unobtrusively whilst cleaning the floor.
In performing this task, a robotic cleaner has to navigate the area which it is required to clean. Robots are usually provided with a number of sensors that enable them to navigate around an environment. A large variety of sensors have been employed on robots to assist with navigation. For example, some robots utilise infra-red detectors that allow the robot to navigate towards an IR beacon, and some robots use complex vision systems that utilise cameras to view, understand and navigate around a local environment surrounding the robot.
Robots are often required to negotiate obstacles within the environment in which they are placed. For example it is usual for robot vacuum cleaners to have to contend with furniture such as chairs, sofas and tables. Because robot cleaners are intended to work as autonomously as possible, they typically have dimensions that will allow them to pass underneath some low-clearance obstacles in order that they can continue to clean underneath without requiring any user involvement.